test: fix syntax tests so they work when testing against builds repo (#1571)
test: fix syntax tests so they work when testing against builds repo (#1571)

When running tests against the builds repo, the package.json and yarn.lock files get updated.
The syntax check only really cares about modifications to files in the syntaxes folder.
angular/vscode-ng-language-service,angular/vscode-ng-language-service,angular/vscode-ng-language-service,angular/vscode-ng-language-service